CHeriCoS

Open Library recently announced the availability of a RESTful API to access Open Library book metadata in RDF/XML format, which combines elements of the Dublin Core metadata terms with some elements from bibliontology and the registered RDA schemas.

This service is in an early stage. The given example returns a nice RDF/XML, but without namespace declarations, whereas this book of Edgar Allan Poe returns a RDF/XML with declarations.

Open Library offers several identifiers for their entries like Dewey, LC, ISBN 10, ISBN 13, LCCN, IA & OCLC, so this service could be very helpful when making mashups of data from museums, archives and libraries.

As I read in Ivan Hermann's Blog, Thomson Reuters will release the fourth iteration of Open Calais in January 2009. Open Calais is a free web-service that takes unstructured text, extracts persons, places, events etc. from it and returns those entities in RDF-style.

Such services can play a key part in the task to charge the semantic web with non-structured content. Meanwhile many interesting applications and tools popped up that use the Calais API in the background. An interesting thing is the semantic proxy that generates RDF from normal websites on the fly. A Firefox and Internet Explorer Add-on called Gnosis provides the same functionality as a browser plugin. Of course there is also a drupal module to auto-tag content on a website (the open calais site itself is powered by Drupal too). This module uses the well-known ARC2-engine as backend, which is a triplestore for PHP/mySQL developed by SemSol aka Benjamin Nowack.